Semiconductor Device and Method for Manufacturing the Same

ABSTRACT

The invention relates to a semiconductor device and a method for manufacturing such a semiconductor device. A semiconductor device according to an embodiment of the invention may comprise: a substrate; a device region located on the substrate; and at least one stress introduction region separated from the device region by an isolation structure, with stress introduced into at least a portion of the at least one stress introduction region, wherein the stress introduced into the at least a portion of the at least one stress introduction region is produced by utilizing laser to illuminate an amorphized portion comprised in the at least one stress introduction region to recrystallize the amorphized portion. The semiconductor device according to an embodiment of the invention produces stress in a simpler manner and thereby improves the performance of the device.

FIELD OF THE INVENTION

The invention relates to a semiconductor device. The invention alsorelates to a method for manufacturing such a semiconductor device.

BACKGROUND OF THE INVENTION

With the development of semiconductor integrated circuits, higherrequirements are raised for the performance of a semiconductor device,especially the speed of the device. In order to improve the performanceof a semiconductor device, techniques have been proposed to introducemechanical stress in the semiconductor device, e.g. in a channel of atransistor. These techniques of introducing stress comprise using astress liner on top and embedding a semiconductor into a source/drainregion.

However, these techniques of introducing stress increase the complexityof the process for manufacturing a semiconductor device, and at the sametime cannot be applied in various integrated circuits due to processlimitation.

SUMMARY OF THE INVENTION

An object of the invention is to overcome at least some of the abovedrawbacks and provide an improved semiconductor device and a method formanufacturing the same.

According to an aspect of the invention, there is provided a method formanufacturing a semiconductor device comprising providing a substrate;forming a device region and forming at least one stress introductionregion separated from the device region on the substrate; forming anisolation structure between the device region and the at least onestress introduction region; amorphizing at least a portion of the atleast one stress introduction region; and recrystallizing the amorphizedportion of the at least one stress introduction region by laser, therebyintroducing stress into the at least one stress introduction region.

In the method for manufacturing a semiconductor device, at least aportion of the at least one stress introduction region is amorphized,and laser is utilized to illuminate the amorphized portion of the atleast one stress introduction region to recrystallize the amorphizedportion, thereby introducing stress into the at least one stressintroduction region. In other words, the invention proposes a techniqueof producing stress by utilizing laser to achieve a selectiverecrystallization. As compared to the prior art, such a technique issimpler and can be widely used in the fabrication of various integratedcircuits.

According to an embodiment of the invention, the substrate may be asemiconductor substrate, and forming a device region and forming atleast one stress introduction region separated from the device region onthe substrate may comprise: patterning at least a portion of the upperpart of the semiconductor substrate, thereby forming the device regionand the at least one stress introduction region separated from thedevice region.

According to another embodiment of the invention, forming a deviceregion and forming at least one stress introduction region separatedfrom the device region on the substrate may comprise: forming asemiconductor layer on the substrate; and patterning at least a portionof the semiconductor layer, thereby forming the device region and the atleast one stress introduction region separated from the device region.

According to a further embodiment of the invention, forming an isolationstructure between the device region and the at least one stressintroduction region may comprise: filling the spacing between the deviceregion and the at least one stress introduction region with adielectric.

According to a further embodiment of the invention, at least a portionof the at least one stress introduction region may be amorphized byselectively implanting ions into the at least a portion of the at leastone stress introduction region.

According to a further embodiment of the invention, a cap layer at leastcovering the device region may be formed before at least a portion ofthe at least one stress introduction region is amorphized. The cap layermay for example comprise a metal layer capable of reflecting laser. Thecap layer may, for example, also comprise a buffer layer below the metallayer.

According to a further embodiment of the invention, a semiconductordevice structure may be formed in the device region after the deviceregion is formed in the substrate.

According to a further embodiment of the invention, a semiconductordevice structure may be formed in the device region after the isolationstructure is formed between the device region and the at least onestress introduction region.

According to a further embodiment of the invention, the cap layer may beremoved after the amorphized portion of the at least one stressintroduction region is recrystallized and thereby stress is introducedinto the at least one stress introduction region. After the cap layer isremoved, a semiconductor device structure may be formed in the deviceregion.

According to another aspect of the invention, there is provided asemiconductor device comprising a substrate; a device region located onthe substrate; and at least one stress introduction region separatedfrom the device region by an isolation structure, with stress introducedinto at least a portion of the at least one stress introduction region,wherein the stress introduced into the at least a portion of the atleast one stress introduction region is produced by utilizing laser toilluminate an amorphized portion comprised in the at least one stressintroduction region to recrystallize the amorphized portion.

According to an embodiment of the invention, the substrate may be asemiconductor substrate, and the device region and the at least onestress introduction region may be formed in the upper part of thesemiconductor substrate.

According to another embodiment of the invention, the semiconductordevice may further comprise a semiconductor layer formed on thesubstrate, with the device region and the at least one stressintroduction region formed in the semiconductor layer.

According to a further embodiment of the invention, the isolationstructure may comprise a dielectric filled in the spacing between thedevice region and the at least one stress introduction region.

According to a further embodiment of the invention, the device regionmay comprise a semiconductor device structure formed therein.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, features and advantages of the invention willbecome more apparent from the following detailed description of theexemplary embodiments of the invention with reference to theaccompanying drawings. In the drawings:

FIG. 1 shows the first step of a method for manufacturing asemiconductor device according to an exemplary embodiment of theinvention, in which a substrate is provided;

FIGS. 2A and 2B show the second step of the method for manufacturing asemiconductor device according to an exemplary embodiment of theinvention, in which a device region is formed and at least one stressintroduction region separated from the device region is formed on thesubstrate;

FIG. 3 shows the third step of the method for manufacturing asemiconductor device according to an exemplary embodiment of theinvention, in which an isolation structure is formed between the deviceregion and the at least one stress introduction region;

FIG. 4 shows the optional fourth step of the method for manufacturing asemiconductor device according to an exemplary embodiment of theinvention, in which a cap layer covering at least the device region isformed;

FIG. 5 shows the fifth step of the method for manufacturing asemiconductor device according to an exemplary embodiment of theinvention, in which at least a portion of the at least one stressintroduction region is amorphized;

FIG. 6 shows the sixth step of the method for manufacturing asemiconductor device according to an exemplary embodiment of theinvention, in which laser is utilized to illuminate the amorphizedportion of the at least one stress introduction region to recrystallizethe amorphized portion;

FIG. 7 shows a schematic cross section view of a semiconductor deviceaccording to an exemplary embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments of the invention will be described in detail withreference to the accompanying drawings hereinafter. The drawings areschematic and not drawn to scale, and just for illustrating theembodiments of the invention and are not intended to limit theprotective scope of the invention. In the drawings, like referencenumerals denote identical or similar components. For making thetechnical solution of the invention clearer, process steps and devicestructures known in the art are omitted herein.

Firstly, a method for manufacturing a semiconductor device according toan exemplary embodiment of the invention will be described in detailwith reference to FIGS. 1-6.

FIG. 1 shows a first step of a method for manufacturing a semiconductordevice according to an exemplary embodiment of the invention. In thisstep, a substrate 101 is provided. The substrate 101 may be formed froma semiconductor material. For example, the substrate 101 may comprise,but not limited to, a material or a combination of materials selectedfrom a group made up of the following materials: silicon, silicongermanium, silicon carbide, etc. The substrate 101 may also be made fromother materials. For example, the substrate 101 may comprise, but notlimited to, a material or a combination of materials selected from agroup made up of the following materials: sapphire, glass, organicmaterial. The substrate 101 may also be formed by stacking a pluralityof layers as desired. For example, the substrate 101 may comprise aninsulating layer and a semiconductor layer located on the insulatinglayer, thereby forming a so-called SOI substrate.

FIGS. 2A and 2B show the second step of the method for manufacturing asemiconductor device according to an exemplary embodiment of theinvention. In this step, a device region 102 is formed and at least onestress introduction region 103 separated from the device region 102 isformed on the substrate 101. The device region 102 is a region forforming a semiconductor device structure, which semiconductor devicestructure may be a transistor, MEMs device, etc. The number of thestress introduction region 103 to be formed may be selected as desiredor according to a particular application. Only one stress introductionregion may be formed, and also multiple stress introduction regions maybe formed.

In an example, the substrate 101 may be a semiconductor substrate. Inthis case, at least a portion of the upper part of the semiconductorsubstrate 101 may be amorphized, thereby forming the device region 102and the at least one stress introduction region 103 separated from thedevice region 102, as shown in FIG. 2A.

In another example, a semiconductor layer may first be formed on thesubstrate 101 and then at least a portion of the semiconductor layer ispatterned, thereby forming the device region 102 and the at least onestress introduction region 103 separated from the device region 102, asshown in FIG. 2B.

It is to be noted that, while the device region and the stressintroduction region may be formed at the same time in certainembodiments of the invention, the invention is not limited thereto.Those skilled in the art may select the sequence of formation of thedevice region and the stress introduction region as desired or accordingto a particular application. For example, the device region may first beformed, and then the stress introduction region separated from thedevice region is formed.

As described previously, the device region 102 is a region for forming adesired semiconductor device structure. In a method for manufacturing asemiconductor device according to an exemplary embodiment of theinvention, a choice may be made as to when to form a desiredsemiconductor device structure as desired or according to a particularapplication. For example, a desired semiconductor device structure suchas a transistor may be formed in the device region 102 after the deviceregion 102 is formed on the substrate 101.

FIG. 3 shows the third step of the method for manufacturing asemiconductor device according to an exemplary embodiment of theinvention. In this step, an isolation structure 104 is formed betweenthe device region 102 and the at least one stress introduction region103.

The isolation structure 104 may be for example a shallow trenchisolation (STI) structure. In an example, the isolation structure 104may be formed by filling the spacing between the device region 102 andthe at least one stress introduction region 103 with a dielectric.

Of course, those skilled in the art may also select the type of theisolation structure as desired or according to a particular application.For example, the isolation structure may also be a field oxide.

As described previously, in a method for manufacturing a semiconductordevice according to an exemplary embodiment of the invention, a choicemay be made as to when to form a desired semiconductor device structureas desired or according to a particular application. In an example, asemiconductor device structure such as a transistor may be formed in thedevice region 102 after the isolation structure 104 is formed.

It is to be noted that, for the sake of simplicity, an illustration isshown in FIG. 3 taking as an example the situation in which the deviceregion and the stress introduction region are formed by patterning thesemiconductor layer formed on the substrate (as shown in FIG. 2B).However, though not shown, the step as shown in FIG. 3 applies equallyto the situation in which the upper part of the semiconductor substrateis patterned to form the device region and the stress introductionregion (as shown in FIG. 2A). This is also the case for FIGS. 4-6.

FIG. 4 shows the optional fourth step of the method for manufacturing asemiconductor device according to an exemplary embodiment of theinvention. In this optional step, a cap layer 105 at least covering thedevice region 102 is formed. The cap layer 105 may be used as a mask forprotecting the device region 102 in a subsequent process step to shieldthe device region 102 from being amorphized or being illuminated bylaser.

In an example, the cap layer 105 may comprise a metal layer 105 bcapable of reflecting laser. The metal layer 105 b may comprise, but notlimited to, a material or a combination of materials selected from agroup made up of the following materials: Al, W, Ti.

In another example, the cap layer 105 may further comprise a bufferlayer 105 a located below the metal layer 105 b. The buffer layer 105 amay comprise, but not limited to, a material or a combination ofmaterials selected from a group made up of the following materials:SiO₂, Si₃N₄.

FIG. 5 shows the fifth step of the method for manufacturing asemiconductor device according to an exemplary embodiment of theinvention. In this step, at least a portion of the at least one stressintroduction region 103 is amorphized. In FIG. 5, a reference sign 103′is used to the already amorphized portion of the stress introductionregion.

In an example, at least a portion of the at least one stressintroduction region 103 may be amorphized by selectively implanting ionsinto the at least a portion of the at least one stress introductionregion (as shown by the arrows in FIG. 5). The injected ions may be Geor Xe. The energy of the ions may be 50 to 400 KeV. The dosage ofinjection may for example be larger than 1×10¹⁴ cm⁻². It is to be notedthat, the invention is not limited to the above example, and at least aportion of the at least one stress introduction region may be amorphizedby other methods known to those skilled in the art.

As described previously, before the step of amorphizing, the optionalstep as shown in FIG. 4 may be performed to form a cap layer 105 atleast covering the device region 102, which cap layer may be used as amask to shield the device region 102 from being amorphized. In FIG. 5the cap layer 105 is also shown. However, it is to be noted that thestep for forming a cap layer is not necessary, and the device region maybe masked in other ways. For example, before amorphizing, a covering maybe disposed directly over the device region and at a distance from thedevice region, thereby shielding the device region from beingamorphized.

While it is shown in FIG. 5 that all the stress introduction regions areamorphized to form amorphized stress introduction regions 103′, it is tobe noted that the invention is not limited thereto. Those skilled in theart may select the portion of the stress introduction regions needed tobe amorphized as desired or according to a particular application. Thatis to say, at least a portion of the at least stress introduction regionmay be amorphized by the step of amorphizing of the method formanufacturing a semiconductor device according to an exemplaryembodiment of the invention.

FIG. 6 shows the sixth step of the method for manufacturing asemiconductor device according to an exemplary embodiment of theinvention. In this step, laser is utilized to illuminate the amorphizedportion of the at least one stress introduction region to recrystallizethe amorphized portion to form a recrystallized portion 103″, therebyintroducing stress into the at least one stress introduction region.

In an example, the wavelength of the laser used may for example be in arange of 200 nm to 600 nm. The temperature at which the amorphizedportion of the stress introduction region is recrystallized byillumination with laser is for example higher than 1400. However, theinvention is not limited thereto. Those skilled in the art may selectthe wavelength of the laser used and the temperature ofrecrystallization, etc. as desired or according to a particularapplication.

As shown by the arrows in FIG. 6, the stress introduced into the stressintroduction region may act upon the device region 102, therebyimproving the performance of the semiconductor device structure formedin the device region. For example, in the case of the semiconductordevice structure formed in the device region being a transistor, thestress introduced into the stress introduction region may act upon achannel of the transistor, thereby increasing the mobility of carriersin the channel to improve the speed of the device.

As described previously, optionally a cap layer 105 at least coveringthe device region 102 may be formed, which cap layer may be used as amask to shield the device region 102 from being illuminated by laser. InFIG. 6, the cap layer 105 is also shown. However, it is to be noted thatthe cap layer is not necessary, and the device region may also be maskedin other ways. For example, before illumination with laser, a coveringmay be disposed directly over the device region and at a distance fromthe device region, thereby shielding the device region from beingilluminated by laser.

In an example in which a cap layer is formed, optionally, the cap layermay be removed after the amorphized portion of the at least one stressintroduction region is recrystallized and thereby stress is introducedinto the at least one stress introduction region.

As described above, in a method for manufacturing a semiconductor deviceaccording to an exemplary embodiment of the invention, a choice may bemade as to when to form a desired semiconductor device structure asdesired or according to a particular application. In an example, asemiconductor device structure such as a transistor may be formed in thedevice region after the cap layer is removed or the covering disposedover the device region is removed.

In the method for manufacturing a semiconductor device according to anexemplary embodiment of the invention as shown in FIGS. 1-6, at least aportion of the at least one stress introduction region is amorphized,and laser is utilized to illuminate the amorphized portion of the atleast one stress introduction region to recrystallize the amorphizedportion, thereby introducing stress into the at least one stressintroduction region. Thus, the invention proposes a technique ofproducing stress by utilizing laser to achieve a selectiverecrystallization. As compared to the prior art, such a technique issimpler and can be widely used in the fabrication of various integratedcircuits.

In the following, a semiconductor device according to an exemplaryembodiment of the invention will be described in detail with respect toFIG. 7.

FIG. 7 shows a schematic cross section view of a semiconductor deviceaccording to an exemplary embodiment of the invention. The semiconductordevice may for example be formed by the method for manufacturing asemiconductor device according to an exemplary embodiment of theinvention as shown in FIGS. 1-6.

As shown in FIG. 7, the semiconductor device according to an exemplaryembodiment of the invention may comprise: a substrate 101; a deviceregion 102 located on the substrate 101; and at least one stressintroduction region 103″ separated from the device region 102 by anisolation structure 104, with stress introduced into at least a portionof the at least one stress introduction region. Therein the stressintroduced into the at least a portion of the at least one stressintroduction region is produced by utilizing laser to illuminate aamorphized portion comprised in the at least one stress introductionregion to recrystallize the amorphized portion.

The device region 102 may for example comprise a semiconductor devicestructure formed therein. The semiconductor device structure may forexample be a transistor, MEMs device, etc.

The isolation structure may for example be a shallow trench isolation(STI) structure. In an example, the isolation structure comprises adielectric filled in the spacing between the device region 102 and theat least one stress introduction region 103″. Of course, those skilledin the art may also select the type of the isolation structure asdesired or according to a particular application. For example, theisolation structure may also be a field oxide.

As shown by the arrows in FIG. 7, the stress introduced into the stressintroduction region may act upon the device region 102, therebyimproving the performance of the semiconductor device structure formedin the device region. For example, in the case of the semiconductordevice structure formed in the device region being a transistor, thestress introduced into the stress introduction region may act upon achannel of the transistor, thereby increasing the mobility of carriersin the channel to improve the speed of the device.

In an example, the substrate 101 may be a semiconductor substrate, andthe device region 102 and the at least one stress introduction region103″ are formed in the upper part of the semiconductor substrate.

In another example, the semiconductor device may further comprise asemiconductor layer formed on the substrate 101, with the device region102 and the at least one stress introduction region 103″ formed in thesemiconductor layer, as shown in FIG. 7.

While the exemplary embodiments of the invention have been described indetail with reference to the drawings, such a description is to beconsidered illustrative or exemplary and not restrictive; the inventionis not limited to the disclosed embodiments. Various embodimentsdescribed in the above and the claims may also be combined. Othervariations to the disclosed embodiments can be understood and effectedby those skilled in the art in practicing the claimed invention, from astudy of the drawings, the disclosure, and the appended claims, whichvariations also fall within the protective scope of the invention.

In the claims, the word “comprising” does not exclude the presence ofother elements or steps, and “a” or “an” does not exclude a plurality.The mere fact that certain measures are recited in mutually differentdependent claims does not indicate that a combination of these measurescannot be used to advantage.

What is claimed is:
 1. A method for manufacturing a semiconductordevice, comprising: providing a substrate; forming a device region andforming at least one stress introduction region separated from thedevice region on the substrate; forming an isolation structure betweenthe device region and the at least one stress introduction region;amorphizing at least a portion of the at least one stress introductionregion; and recrystallizing the amorphized portion of the at least onestress introduction region by laser, thereby introducing stress into theat least one stress introduction region.
 2. The method for manufacturinga semiconductor device as claimed in claim 1, wherein the substrate is asemiconductor substrate, and wherein forming a device region and formingat least one stress introduction region separated from the device regionon the substrate comprises: patterning at least a portion of the upperpart of the semiconductor substrate, thereby forming the device regionand the at least one stress introduction region separated from thedevice region.
 3. The method for manufacturing a semiconductor device asclaimed in claim 1, wherein forming a device region and forming at leastone stress introduction region separated from the device region on thesubstrate comprises: forming a semiconductor layer on the substrate; andpatterning at least a portion of the semiconductor layer, therebyforming the device region and the at least one stress introductionregion separated from the device region.
 4. The method for manufacturinga semiconductor device as claimed in claim 1, wherein forming anisolation structure between the device region and the at least onestress introduction region comprises: filling the spacing between thedevice region and the at least one stress introduction region with adielectric.
 5. The method for manufacturing a semiconductor device asclaimed in claim 1, wherein at least a portion of the at least onestress introduction region is amorphized by selectively implanting ionsinto the at least a portion of the at least one stress introductionregion.
 6. The method for manufacturing a semiconductor device asclaimed in 1, wherein a cap layer at least covering the device region isformed before the step of amorphizing at least a portion of the at leastone stress introduction region.
 7. The method for manufacturing asemiconductor device as claimed in claim 6, wherein the cap layercomprises a metal layer capable of reflecting laser.
 8. The method formanufacturing a semiconductor device as claimed in claim 7, wherein thecap layer also comprise a buffer layer below the metal layer.
 9. Themethod for manufacturing a semiconductor device as claimed in claim 1,further comprising forming a semiconductor device structure in thedevice region after the device region is formed in the substrate. 10.The method for manufacturing a semiconductor device as claimed in claim1, further comprising forming a semiconductor device structure in thedevice region after the isolation structure is formed between the deviceregion and the at least one stress introduction region.
 11. The methodfor manufacturing a semiconductor device as claimed in claim 6, furthercomprising removing the cap layer after the amorphized portion of the atleast one stress introduction region is recrystallized and therebystress is introduced into the at least one stress introduction region.12. The method for manufacturing a semiconductor device as claimed inclaim 11, further comprising forming a semiconductor device structure inthe device region after the cap layer is removed.
 13. A semiconductordevice comprising: a substrate; a device region located on thesubstrate; and at least one stress introduction region separated fromthe device region by an isolation structure, with stress introduced intoat least a portion of the at least one stress introduction region,wherein the stress introduced into the at least a portion of the atleast one stress introduction region is produced by utilizing laser toilluminate an amorphized portion comprised in the at least one stressintroduction region to recrystallize the amorphized portion.
 14. Thesemiconductor device as claimed in claim 13, wherein the substrate is asemiconductor substrate, and the device region and the at least onestress introduction region are formed in the upper part of thesemiconductor substrate.
 15. The semiconductor device as claimed inclaim 13, wherein the semiconductor device further comprises asemiconductor layer formed on the substrate, with the device region andthe at least one stress introduction region formed in the semiconductorlayer.
 16. The semiconductor device as claimed in claim 13, wherein theisolation structure comprises a dielectric filled in the spacing betweenthe device region and the at least one stress introduction region. 17.The semiconductor device as claimed in claim 13, wherein the deviceregion comprises a semiconductor device structure formed therein. 18.The semiconductor device as claimed in claim 14, wherein the deviceregion comprises a semiconductor device structure formed therein. 19.The semiconductor device as claimed in claim 15, wherein the deviceregion comprises a semiconductor device structure formed therein. 20.The semiconductor device as claimed in claim 16, wherein the deviceregion comprises a semiconductor device structure formed therein. 21.The method for manufacturing a semiconductor device as claimed in claim2, wherein cap layer at least covering the device region is formedbefore the step of amorphizing at least a portion of the at least onestress introduction region.
 22. The method for manufacturing asemiconductor device as claimed in claim 3, wherein cap layer at leastcovering the device region is formed before the step of amorphizing atleast a portion of the at least one stress introduction region.
 23. Themethod for manufacturing a semiconductor device as claimed in claim 4,wherein a cap layer at least covering the device region is formed beforethe step of amorphizing at least a portion of the at least one stressintroduction region.
 24. The method for manufacturing a semiconductordevice as claimed in claim 5, wherein a cap layer at least covering thedevice region is formed before the step of amorphizing at least aportion of the at least one stress introduction region.